Postoperative elevation of amylase/creatinine clearance ratio in patients without pancreatitis.

An elevated CAm/CCr ratio has been used as evidence for the frequent occurrence of acute pancreatitis in the postoperative period. We measured CAm/CCr pre and postoperatively in 28 patients undergoing extraperitoneal surgical procedures. None of the patients had clinical evidence of pancreatitis, although 2 of the 28 patients had elevated CAm/CCr ratios preoperatively. Mean CAm/CCr rose from a preoperative level of 2.3 +/- 0.3% (1 SE) to 3.2 +/- 0.3% on the first postoperative day (P less than 0.001). Of the 26 patients with normal preoperative CAm/CCr, 12% (3 of 26) developed a clearly abnormal ratio and 12% (3 of 26) developed borderline elevated values. An elevated CAm/CCr appears to be a nonspecific postoperative finding and cannot be used as evidence of acute pancreatitis during this period.